Marine structures require materials that are subject to severe coastal conditions. Material selection is dependent on the level of exposure at the site and the expected usage of the site:
High profile areas require a higher level of finish and materials.
Beach locations are subject to direct and severe weather conditions and corrosive environments.
Canal and river systems are less subject to the direct severe weather, but are still subject to the corrosive environment.
Seek professional advice regarding selection of stones for marine structures. Avoid stone faces with protrusions which may cause injury.
See Table 3: Materials for water access facilities for further guidance.
Protective coatings may also enhance the appearance of the substrate to which it is applied (such as concrete and galvanised steel).
Two part coating systems on concrete and steel give resistance to water, alkali and acids.
An effective coating must provide the desired protection level against environmental and chemical damage, for as long as possible.
Good adhesion to the surface, resistance to moisture and untraviolet (sunlight) are essential.
In aggressive environments both epoxy and polyurethane two part coating systems offer significant advantages over one-component coatings.
Epoxy coatings are formulated based upon the performance requirements for the end product.
One component coatings rely on drying or surface oxidation to cure.
Two part coating systems
With both epoxy and polyurethane two part coating systems (solvent free and solvent-based types) the base resin and a hardener are combined just prior to application.
Once applied to the surface the coating cures immediately in solvent-free products.
In solvent based systems the coating cures after solvents have evaporated from the film.
Generally polyurethane systems cure faster than their epoxy counter-parts however they can be difficult to use when cured in moist conditions at low temperatures.
Two part epoxy and polyurethane coating systems are preferred over conventional one component products due to their superior mechanical properties and protection against long term environmental degradation.
All solvents are potentially hazardous and care should be taken to apply solvent-based systems in a well ventilated area.
See Table 2: Materials for marine structures for further guidance.
Note: Liaise with Council (Development Services) to determine the acceptability of various materials for particular applications, particularly timber and galvanised steel.
Table 2: Materials for marine structures
Materials
Key considerations
Recommended applications
Stainless steel
where a high level finish is required, steelwork is to be marine grade SS316, No.6 finish and electro polished.
handrails. barrier rails
Concrete (in-situ and per-cast)
use high strength (50 MPa and above) low water to binder ratio concrete mixes to limit crack width and to withstand regular water only pressure cleaning. Oil or other contamination is to be spot cleaned prior to pressure cleaning to ensure it is not washed into a waterway
use chemical absorption agents in the concrete mix
use pore blockers (admixtures) to wet concrete, or surface application
paint concrete members
use galvanised steel, stainless steel, plastic filament and carbon fibre reinforcement
sealers are not to be used on any boat ramp. To protect a concrete area not related to a boat ramp, coat with a two part epoxy coating system to give resistance to water, alkali and acids. Ensure a non-slip transparent sealant is used
cover for reinforced concrete must be in the range 25-40 mm, Salt water exposure 65 mm min. as per AS:3600:2009 Concrete structures
encapsulate pre-stressed tendons within grout or watertight plastic conduit
consider cathodic protection for structures, as per AS 3600, this will avoid significant deterioration during the typical lifespan of the structure. It is designed to halt and prevent all active corrosion that may occur.
high profile, high use areas – boat ramps jetties, floating walkways, pontoons.
Timber
shorter lifespan than concrete or steel. Reduced life cycle (subject to decay and infestation)
AS 5604:2005 Timber natural durability ratings. Hardwood timbers are to be durability class 1 or 2 in accordance with AS 1720.1:2010 Timber structures, Design methods
requires careful selection of hazard rating for the specific application (see LIM Bollards). Requires coating with Ultradeck, Lanotec or approved equivalent less cost effective than concrete.
identified areas wash down areas, temporary vehicle and pedestrian beach access.
Aluminium
specify marine grade aluminium including corrosion protection to minimise premature component failure
specify aluminium fixings or separate different metals with nylon washers / sleeves to prevent galvanic corrosion
100% recyclable, can be re-used endlessly.
jetties, floating walkways, pontoons, stairs.
Recycled plastic and fibre composite
long warranted life cycle (no historical information available)
suitable for stair treads, small craft skids, platforms.
identified areas jetties, floating walkways, pathways, boat ramps, stairs, viewing platforms, shower bases, wash down areas, temporary and permanent vehicle beach access.
Galvanised Steel
cost effective
long life, durable, reduced maintenance
select hot dipped galvanised (after fabrication) steel for low usage low profile sites
coat with a two part epoxy coating system for superior protection against long term environmental degradation.
low use, low profile areas - stairs, viewing platforms, shower bases, wash down areas
Stone
seek professional advice for selection of stone which does not disintegrate in contact with salt water
select stone faces which are essentially flat (avoid protrusions).
revetment walls, boat ramp batters.
Table 3: Materials for water access facilities
Element
Corrosion resistant materials
Stair treads and platforms/sunken landings
marine grade aluminium open grating with floor plate nosing. With larger openings, less marine growth will be encountered
aqua deck (or approved equivalent), recycled plastic or fibre composite material
fixings to be 316 marine grade stainless steel or insert to prevent contact with aluminium (prevents galvanic corrosion)
Handrail
low volume locations - marine grade alloy pipe including a two part epoxy coating system for extended rust protection
medium volume locations - marine grade aluminium
high volume / high profile locations - 316 marine grade stainless steel
Slides/mats
soft rubber matting
other appropriate material such as recycled plastic
Pulley system
HDG steel (after market) cord/wire
316 marine grade stainless steel
Watercraft wash down
posts - HDG (after market) steel with two part epoxy coating
watercraft cradle - rubber mat or artificial turf
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Sunshine Coast Open Space Landscape Infrastructure Manual (LIM) DISCLAIMER
Disclaimer
Information contained in this document may change without notice and you should use the current material available from Council’s website and not rely on material previously printed or stored by you.
All figures and diagrams are intended to be used as an aid to design and include Council’s preferred elements but they are not intended to be prescriptive and may need to be varied as dictated by site specific factors. While Council has exercised reasonable care in preparing this document, it does not warrant or represent that it is accurate or complete. The Council will not accept responsibility for any loss, damage, cost or expense that you may incur as a result of the use of or reliance upon any material contained in this document.
This document is produced to convey general information and is not intended to constitute advice whether professional or legal. Any reference to legislation in this document is not an interpretation of the law. It is to be used as a guide only. Consult relevant authority websites for current documents, revisions and amendments.
Where a particular product or supplier is profiled in this document, Council is NOT nominating this product or supplier as the selected choice. Product/supplier information has been provided to allow users to source products which contain the correct elements required for Council embellishments. Each product profiled states ‘or equivalent’ which means that different products may be supplied provided they satisfy the identified performance criteria, recommended standards, equal access guidance and product specifications.
Product design, manufacture and installation requires appropriately qualified people to provide site specific solutions to ensure the embellishment is appropriately adapted to local conditions and data.
This document does not override requirements stipulated in a development approval. Project specific variations may be appropriate as a result of site, environmental or other constraints. Any variations to these standards must be approved in writing by council prior to commencement of variation works. Components of this document may be used within a contract document but users should undertake their own investigations to confirm the information is suitable for this purpose.
Drawings contained in this document are NOT FOR CONSTRUCTION.
Details in this document are deemed to be the minimum standard and the user may wish to apply a higher standard subject to approval by council.
Acknowledgements
Council wishes to thank all contributors and stakeholders involved in the development of this document.
Copyright
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